I ran into the same issue with the official Creative drivers with my HD. I removed, cleaned, and re-installed the Creative drivers several times to no luck.

I was about to do a total reformat when I tried the PAX drivers out of desperation. They worked without a problem. The HD is an awesome card but it's too bad the official drivers don't work (or at least they didn't at the time).

I honestly can say i've never had a issue with any of my creative x-fi cards on Windows 7. Well except twice which were only due to user errors. (Didnt install that silly thing to detect that card)
I have owned:
X-Fi xtremegamer
X-Fi xtremeMusic
X-Fi Titanium Fatality Champ which is just a Titanium with X-ram
and now a X-Fi Titanium HD